David Cameron at the G8 dementia summit in London, 11 December 2013. Photograph: Andy Rain/EPA

I applaud the Alzheimer's Society's call for a seven-fold increase in research funding into dementia ('Put dementia on same footing as cancer, says charity', 11 December). I've heard carers describe living with the dementia of their loved ones as akin to a living bereavement. More funding for research that might delay the onset of the disease – or, in some cases, stop its onset at all – would be wonderful.

But what about other mental illnesses? David Cameron has laid down his excellent Dementia Challenge – but where is the aspiration among politicians for a Mental Health Challenge?

It is an unpalatable truth that in so-called "civilised" societies people with mental illness may not live long enough to develop dementia. Chronic underfunding of mental healthcare has led to lower treatment rates, and people with severe mental illness have a reduced life expectancy of 15-20 years.

Mental illness is responsible for the largest proportion of the disease burden in the UK. Yet a recent review found that mental health research received just 6.5% of total funding – compared with 25% for cancer. I urge governments, leaders and decisionmakers to ensure that increased funding reaches all areas of mental health – and puts it on an equal footing with physical health.Professor Sue BaileyPresident, Royal College of Psychiatrists

• The case for a more effective response to dementia is unanswerable. However, there are worrying signs that the debate is dominated by biomedical perspectives on the one hand and palliative care on the other. While dementia may well turn out to have biochemical or genetic causes, it is at least possible that it also has social or environmental causes. The search for a magic bullet led by clinicians and supported for obvious reasons by big pharma repeatedly directs attention away from the need to devise holistic approaches to what are almost invariably wicked problems.

A significant proportion of the global burden of disease, communicable and non-communicable would be avoidable if only political solutions could be found to, for instance poverty, hunger, pollution and unemployment. Without denying a role for drugs or other medical interventions, part of an effective response to dementia may also lie in a society where people are enabled to attain their full capabilities.Neil BlackshawLittle Easton, Essex

•Your coverage of the G8 dementia summit has been welcome. However, as with many others, you have failed to consider the experience of black and minority ethnic older people, whose numbers are on the increase in the UK.

A recent Race Equality Foundation briefing paper suggests that while Caribbean and South Asian communities are at higher risk of developing dementia, access to care and support for these older people and their families has been hampered by poor understanding of services within these communities, and by a lack of appropriate and accessible services.

The Race Equality Foundation, with others, has called for action, such as use of "community dementia navigators" to improve the experiences of these people and ease the burden of care; for increased dementia training for health practitioners; co-operation with the voluntary and community sector to spread information relating to diagnosis and treatment; and better engagement of black and minority ethnic communities to overcome the information deficit.Jabeer ButtDeputy chief executive, Race Equality Foundation

• Professor A David Smith (Letters, 11 December) gave a great account of the many ways, some already proven, that people could live better and avoid dementia. The following day's editorial (Dementia: Taking Care, 12 December)seemed to go down the same old road as has been taken with cancer despite Otto Warburg's research into the causes of cancer, for which he won a Nobel prize in 1931. That same old road being millions of pounds poured into research for a cure with drugs (with their attendant side-effects) rather than prevention (the new paradigm), by educating and empowering people to change their lifestyles and diets to avoid getting diseases they expect to get when older. Prevention being better than cure, this is not only a safer, more dignified option. It is, by all accounts, a much cheaper one. Annie WattsKingston on Thames, Surrey